Oil burning device



Jan. 19, 1937.

'8. VALJI- IAN OIL BURNING- DEVICE Filed June 17, 1952 2 Sheets-Sheet 2I0 4 3 o o J a a 4 w 0 7 W 1 6 7 J 8 I 4 7 J 4 2 4 J o w f Peiented Jan.19, 1937 2.008.441 g on. BURNING DEVICE 1 Ben Valjean, Lansing, Michasslgn'or it Motor Wheel Corporation, Lansing, Mi h tion at Michigan 0 ua corpora- Application June 17, 1932, Serial No. 617,802

Claims.

This invention relates to oil burning devices and more particularly todevices of that charac-.

ter suitable for practicing the process of combustion wherein apremixture of oil vapors and air is formed in a premixing chamber andthe premixture thus formed is subsequently burned in a combustionchamber in the presence of an adequate amount of combustion supportingair.

The general object of. this invention may be the provision of an oilburning device of the premixing type wherein relatively perfect andnoiseless combustion of fuel oil is obtained without the escape to thefiues of any unconsumed air or oil vapors. This object is accomplished,in part, by causing a uniform mixture of oil vapors and air to pass at arelatively high velocity into a combustion chamber where combustionsupporting air is introduced into the mixture uniformly in the samedirection as the flow of the mixture and at substantially the same or aslightly greater velocity.

One of the more specific objects of the invention is the provision or anoil burning device adapted to complete combustion in a localized areaand in substantially a horizontal plane.

This object is attained by causing the premixture to pass into thecombustion chamber with a gyratory or spiral motion. Combustionsupporting air is projected into the swirling mixture in a mannerwhereby to accentuate the horizontal or gyratory movement of themixture. Combustion accordingly occurs in a zone of limited verticalextent.

A further object of the invention is the provision in an oil burningdevice of the premixing type of means for automatically controlling therate of vaporization of fuel oil to correspond to the amount of airavailable for mixing with the same. This is accomplished by confiningthe fuel within the premixing chamber whereby to limit the surface areathereof and then passing the air utilized for forming the premixtureover the confined fuel.

Still another object of the invention is the provisio'n of an oilburning device wherein natural draft is utilized to'produce a rotary orgyratory flame. This is accomplished by introducing the premixing airinto an annular passageway containing vapors through holes inclinedhorizontally at an oblique angle to the wall of the chamber whereby theair circulates about the annular passageway forming a premixture of oilvapors and air which passes upwardly into a combustion chamber with aswirling motion.

Combustion supporting air is admitted to the combustion chamber throughholes inclined similarly to the holes in the premixing chamber wherebythe swirling motion of the premixture is to some extent converted to agyratory motion and combustion occurs in a zone of limited ver ticalextent.

Other objects of the invention will in part be obvious and will in partappear hereinafter.

The invention accordingly comprises the fea= tures of construction,combination of elements and arrangement of parts, which will be exemplified in the construction hereinafterset forth and the scope of theapplication of which will be indicated in the appended claims.

For a more complete understanding of the 15 nature and objects of theinvention reference should be had to the following detailed descriptiontaken in connection with the accompanying drawings, in which:

Figure I is a perspective view of an oil buming water heater embodyingthe present invention with a portion of the outer casing cut away toshow the relation of the internal parts.

Figure II is a perspective view of a premixing chamber utilized incombination with the oil burning device shown in Figure I as embodyingthe present invention with parts cut away to show the construction andarrangement oi. the interior of the chamber; and

Figure III is a top plan view of the premixing chamber shown in Figure11.

The oil burning water heater shown in Figure I embodying a preferredform of the present invention consists of a cylindrical outer casing illspaced from a cylindrical inner casing it by a quantity of insulationmaterial I3. The cylindrical casings Ill and l l are secured to abuttomwall it in any suitable manner as by welding the upturned peripheralflange it of the bottom wall to the lowerextremity of the outer casingiii. The upper extremity of the inner casing H is closed by a cover 16provided with a downwardly extending peripheral flange ll whereby thecover is secured to the casing M. The upper extremity of the outercasing it is 5 flanged as indicated at l8 and a circular cover it issecured to the casing l0 within the flange E8; The space between thecovers l6 and i9 is filled with insulation material it.

An annular ring 20 secured to the inner casing ll adjacentthe lowerextremity thereof provides, means for supporting a premixing chamber orburner chamber 2|, the lower extremity of which is preferably spacedslightly above the bottom wall it. The premixing chamber 26 is Gil"chamber 2|.

formed with an outwardly extending annular flange 22 whereby thepremixing chamber is secured to the ring 20. A combustion chamber 23comprising a cylindricalvertical wall 24 and a top wall 25 is positionedabove the premixing chamber 2| and in open communication therewith. Thelower extremity'of the cylindrical wall 24 is seated upon the annularflange 22 of the premixing chamber 2| whereby to support the combustionchamber over the premixing chamber. Suitable means, such as stovecement, is utilized for forming a substantially airtight joint betweenthe lower extremity of the vertical combustion chamber wall 24 and theupper extremity of the premixing chamber 2|..-

Four exhaust flues 26 provide means for the escape from the combustionchamber of the prodnets of combustion. The exhaust fluesare arrangedwith their lower extremity secured within openings provided for thatpurpose in the top wall of the combustion chamber 23 and extendvertically withinthe chamber formed by the inner casing. The upperextremity of the exhaust flues 25 communicate with openings formed in acircular plate 21 which is positioned within the casing adjacent theupper extremity thereof. The plate 21 is provided with an upturnedperipheral flange '28 whereby the plate is secured to the inner casingmember l as by welding, for example. The exhaust flues 26 deliver theproducts of combustion from the combustion chamber to a compartment 30formed between the circular plate 21 and the top wall I8 of the" casingThe products of combustion delivered to the compartment 30 escape to achimney or outlet flue, not shown, through the exhaust pipe 3|.

The plate 21, the casing H, the top and side walls of the combustionchamber 23, and the annular ring 20 secured to the casing define achamber 29 adapted to contain the water to be heated. Water is deliveredto the chamber 29 through a supply pipe 32 and is withdrawn from thechamber through the pipe 33. It will, of course, be understood that thejoints between the various members forming the water chamber 29 aresuitably treated to prevent the escape of water from the chamber 29other than through the outlet pipe 33.

Fuel oil is delivered to the premixing chamber 2| through a fuel inletpipe 34 from a control device 35 connected to a fuel supply tank, notshown, by pipe 36. Suitable mechanism, not shown, is contained withinthe control device 35 for regulating the flow of fuel oil to thepremixing A conventional thermostat, responsive to the temperature ofthe water contained within the chamber 29, may be associated with thecontrol device 35 for operating the mechanism regulating the flow of oilto the premixing chamber 2|. A plunger rod 31 is preferably associatedwith the fuel inlet pipe 34 whereby to clean the same as occasionrequires. An automatic safety device comprising a bimetallic bar, notshown, having one extremity positioned within the premixing chamber 2|and its other extremity associated with the mechanism for controllingthe flow of fuel to the premixing chamber, is positioned within theconduit 38 extending between the control device 35 and the premixingchamber 2|.

The control device 35 is preferably designed to permit a limitedquantity of fuel oil to flow into the premixing chamber 3| at all timeswhereby i-n nrr'wide fuel for a pilot fire. It should, of

course, be understood that any suitable ignition mechanism may beutilized since the details of such mechanism comprise no-part of ,thepresent invention.

When the mechanism controlling the flow of fuel to the premixing chamberthrough the fuel inlet pipe 34 is actuated to permit a flow of fuelsuflicient for the normal operation of the burner and the fuel isignited within the premixing chamber, the heat generated by theresulting combustion causes the liquid fuel entering the combustionchamber to vaporize. The rate of vaporization of the fuel may befacilitated by causing the premixing air entering the premixing chamberthrough the air inlet openings 39 formed in the lower portion of thewall thereof to pass over the liquid fuel. The air admitted through theopenings 39 mixes with the oil vapors generated within the premixingchamber to form a premixture of oil vapors and air.

The exact nature of the premixture thus formed is not definitely linown,although it is believed to be a purely .physical mixture of air and oilvapors. However, certain authorities have expressed a belief that achemical reaction takes place between the oxygen contained in the airand the constituent elements of the fuel oil. Regardless of the reactionwhich occurs between the air and the oil vapors it is known that wherethe quantity of air admitted to the premixing chamber through the inletopenings 39 is less than the total amount of" air required for thecomplete combustion of the oil vapors generated within-thepremixingchamber by-reason of the natural draft created throughthe'outlet flues. It should; of course, be understood that the lowerportions of the casings l0 and H below the annular ring 20 are per-'forated in a suitable manner to permit the entry of an adequate quantityof air into the space surrounding the premixing chamber 2|. As thepremixture passes from the premixing chamber 2| into the combustionchamber 23 combustion supporting air is introduced into the premixturethrough the air inlet openings 40 formed adjacent the upper extremity ofthe premixing chamber 2|. At the maximum oil feed, combustion occurswithin the combustion chamber 23, as illustrated diagrammatically by theflames 4|;

Thefeatures of construction and operation of the device shown in FigureI'thus far described are substantially identical to those found in theprior art. However, as shown in Figures II and III, the specific detailsof construction of the present oil burning 'device differ in severalimportant respects from the prior art structures.

The premixing or'burner chamber 2| is preferably, although notnecessarily, formed of cast metal and is provided with a plurality ofcircumferentially spaced apart vertically extending external ribs 42.The ribs 42 are preferably hollow and of triangular shape in crosssection. The upper extremity of the wall is formed with an internalshoulder 43 and with an external collar portion 44 positionedimmediately below the outwardly extending annular ring 22. A pluralityof circumferentially spaced apart vertically extending ribs .45 similarto the ribs 42 are formed in the collar 44.

2,068,441 aligned with the ribs 42 butma'y lie in a planeintermediatethe ribs 42.

The base of the premixing chamber 2| is formed with a raised centralportion 46 in the shape of a cylinder arranged in concentric relation tothe vertical walls of the chamber. This central portion is preferablyformed integrally with the base and may terminate slightly below the topof the chamber 2| or as here shown may terminate just above the bottomwall. A removable cylinder-like member 41 preferably formed of castmetal and provided with a plurality of horizontally spaced apartoutwardlyextending flanges or baiiie members 48 is positioned upon thecentral portion 46 when it terminates as here shown adjacent the bottomwall. The cylindrical member 41 is formed with a closed. upper extremity48 and the lower extremity thereof is closed by the raised centralportion 46 of the bottom wall of the premixing chamber. A pair ofaligned openings are formed in the central portion 45 and the closedupper extremity 49 of the cylinder 41. A vertical tube 50 is securedwithin these openings with its upper extremity preferably extendingslightly above the wall 49. A removable cap l spaced slightly away fromthe top of the tube 50 is secured within the upper extremity of thetube.

The raised central portion 46 and the cylindrical member 41, thediameter of which is substantially the same as that of the raisedportion 48, form an annular passageway within the premixing chamberbetween the vertical wall thereof and the vertical wall of the raisedportion 46 and the cylindrical member 67. The baiiies 48 carried by thecylindrical member 41 extend into the annular passageway thus formed.

Fuel oil is delivered adjacent the bottom wall of the premixing chamberthrough the fuel supply pipe 34 which communicates with a suitableopening in the vertical wall of the premixing chamber. A pair ofvertically disposed partitions 52 of limited height are positioned oneither side of the opening with which the fuel supply pipe 34communicates. The partitions are disposed between the wall of thepremixing chamber U and the raised central portion 46 whereby to form anopen topped compartment 53 into which fuel oil is discharged by the fuelsupply pipe 34. The upper extremity of the partitions 52 terminatebeneath the lowermost baiile 45..

The mechanism contained within the control device 35 preferablyregulates the flow of fuel to the premixing chamber whereby to preventthe oil rising within the compartment 53 above the partitions 52-. Inthis manner the oil delivered to the premixing chamber is confinedwithin the open topped compartment 53 adjacent the outer wall of thepremixing chamber whereby to limit the exposed surface area of the oil.

The air inlet openings 39 are formed in the external ribs 42 whereby theair admitted therebeing formed in the external ribs 45 whereby agyratory motion is imparted ,to the air entering therethrough similar tothe motion of the air Y entering through the air inlet openings 39.

When oil is delivered to the compartment 53 within theoil burning deviceshown in Figure chamber and air is admitted to the premixing chamber ina substantially horizontal direction toward the center of the chamber,the initial fire within the premixing chamber usually produces a largequantity of smoke and soot because some of the vapors are burned withoutthe necessary combustion supporting air. In the present structure thebafiles 48 retard the escape of the oil vapors generated from thelimited surface of the compartment 53 and the arrangement of the airinlet openings 39 cause the air entering therethrough to circulate tosome extent around the premixing chamber between the baiiles 48 and overthe compartment 53. The bafiles 48 likewise tend to prevent theimmediate escape to the combustion chamber of the mixture of air and oilvapors formed in the premixing chamber whereby ample opportunity isafforded for an adequate supply of combustion supporting air to unitewith the oil vapors. Accordingly, combustioninitially occurs within thepremixing chamber without the formation of soot or smoke.

Once combustion has been initiated within the premixing chamber theresulting heat and air circulating over the compartment 53 cause a veryrapid vaporization of the oil contained within that compartment. Thesurface area of the com-' partment'53 is so related to the size andnumber of air inlet openings 39 that the rate of va-' porization of oilfrom the compartment is substantially proportional to the volume andv'eloc-.

ity of the air passing over the compartment.

This proportion is such that the total quantity i of vapors which may begenerated from the oil contained within the compartment 53 will begreater than the quantity necessary to form a completely combustiblemixture with the air admitted through the air inlet openings 39regardless of the draft conditions affecting the velocity of the airthrough the inlet openings. Combustion therefore occurs within the lowerportion of the premixing chamber 2i for a short time. only andthereafter that portion of the chamber becomes filled with a mixture ofair and oil vapors which will not burn without the addition of a furthersupply of combustion supporting air. As the premixture ascends spirallyabout the central tube toward the combustion chamber its velocity isreduced somewhat and it becomes a more nearlyv uniform mixture as itapproaches the upper region of the premixing chamber where thecombustion supporting air enters. The inclined air inlet openings 40project the combustion supporting air into the swirling uniformpremixture in substantially the same direction as that of the premixturebut at a relatively greater velocity and with a more pronounced gyratorymovement.

Because of the greater velocity of the combustion supporting air itcirculates rapidly throughout the premixture and quickly forms ahomogeneous completely combustible mixture of air and oil vapors whichrotates about the.

'upper region of the premixing chamber and passes into the combustionchamber in a rapidly chamber and are distributed evenly throughout thesame. It'should be observed that for the same reason the combustionchamber need not be as long as similar chambers utilized heretolore,where combustion occurs in a vertical zone rather than a horizontalzone.

Where combustion supportingair is supplied through spaced apart airinlet openings, as herein shown, there is a tendency for a'series ofexplosions to occur adjacent the inlet openings.

This is due to the fact that the streams of air entering throughadjoining openings are separated and unite with the premixture presentto form explosive mixtures alternately close to the openings and remotefrom the openings. This tendency, which produces an objectionable noise,

is avoided in the present device by causing the separate streams of airentering through adjoining air inlet openings 40 to unite with eachother before contacting the premixture passing upwardly to thecombustion chamber. Obviously, various other devices might be utilizedto accomplish this, such as, for example, reducing the velocity of theair admitted through the openings 40.

In the present device a pair of horizontally spaced apart annular rings54 and '55 are positioned, respectively, above and below the air inletopenings 40. The horizontal extent of the rings is sufficient to permitthe inclinedstream of air entering through one inlet opening 40, tounite with the next adjoining stream before they pass'through the gapformed by the rings 54 and 55 into the upper region of the premixingchamber. In this manner the combustion supporting air is delivereduniformly to the premixture. The ring 55 is seated upon the shoulder 43formed adjacent the upper extremity of the vertical wall of the chamber2|. It is secured in position by reason of its complementary engagementwith the shoulder 43 and the adjacent vertical portion of the chamberwall. Ring 54 is seated upon supports 55 and 51 carried by ring 55.

Due to fluctuations in the draft and the heat of combustion there is atendency for down currents or eddies to be set up within the premixingchamber whereby the eflicient operation thereof is impaired. In thepresent device the upper wall 49 of the cylindrical member 41 and thebaflies 48 carried thereby tend to prevent the premixture from eddyingback into the premixing chamber after it has been discharged therefromas just described;

,A small quantity of the premixture collects immediately above the wall49, however, because the wall is spaced below the air inlet openings 40and there is a small region within which down currents may be set up.The premixture'which collects in this region is normally only partiallyburned because there is not sufficient air present to support thecomplete combustion thereof. When this occurs a slight amount of smokeresults and there is frequently a deposit of soot or carbon formed onthe wall 49.

This objectionable formation of soot and smoke is prevented by providinga sufficient amount of combustion supporting air to unite with thepremixture trapped above the wall 49. Air is supplied for this purposethrough the tube 50 which communicates with the atmosphere beneath thepremixing chamber 2!; The cap 5| deflects the air entering through thetube 50 whereby to direct it over the surface of the wall 49.

Whilethe oil burning device embodying the present invention-is designedespecially for use with naturaldraft, it will be obvious that it isequally suited for use with forced draft. Where.

natural draft is used there is a continual fluctuation in the strengthof the draft. This, of course, varies the amount of air admitted throughthe air inlet openings 31 and 40. Ordinarily any substantial variationin the draft would destroy the balance between the oil vapors formed inthe premixing chamber and the total amount of air admitted thereto tosuch an extent that the efllciency of the device would be materiallyimpaired and in some cases practically destroyed.

These undesirable results are obviated in the present construction bylimiting the surface area of the oil and passing the premixing air overthis limited surface whereby the rate of vaporization of the oil, withinwide limits, is p'roportional to the volume and velocity of the airentering and wherein the ra e of vaporization of oil is proportional tothe preferred embodiment of the invention has been shown and described,it should be understood that the invention is not limited thereto but iscoextensive with the scope of the appended' claims.

I claim:-- 1. Combustion apparatus of the character described comprisinga burner chamber having a bottom wall and an annular side wall, the sidewall provided with a plurality of primary air inlet apertures in thelower portion thereof and a plurality of secondary air inlet aperturesadjacent the top thereof, all of said apertures inclined horizontally tothe radius of the burner to give the air admitted therethrough acircumferential direction, a pair of closely spaced air baflle ringslocated inside of the burner above and below the secondary air inletapertures, a fuel receiving sump of limited circumferential and radialextent formed on the bottom wall adjacent the side wall, a wall of theburner being provided with a fuel inlet opening adapted to deliver fuelto said sump, and a horizontally disposed baflie arranged within theburner to partially overlie the top of said sump.

2. Combustion apparatus of the character described comprising a burnerchamber having a bottom wall and an annular side wall, a fuel receivingpump of limited circumferential and radial extent formed on the bottomwall adjacent the side wall, a wall of the burner being provided with owof air. While only the baiiie positionedto partially overlie the sump,said side wall being provided with a' plurality of primary air inletapertures in the lower portion thereof, said apertures being inclinedhorizontally to the radius of the burner to give the air 'admittedtherefrom a circumferential direction and cause the same to circulateover said fuel sump and between said baflles to form a premixture, saidside wall also being provided with a plurality of secondary air inletapertures adjacent the top thereof for admitting additional air to forma combustion mixture, said secondary air inlet apertures being inclinedhorizontally to the radius of the burner in the same direction as saidprimary air inlet apertures.

3. Combustion apparatus of the character described comprising a burnerchamber having a bottom wall and an annular side wall, a fuel receivingsump of limited circumferential and radial extent formed on the bottomwall adjacent the side wall, a wall of the burner being provided with afuel inlet opening adapted to deliver fuel to said sump, a horizontallydisposed'baflle arranged in the center of the burner above said sump andpositioned to partially overlie the sump, said side wall being providedwith a plurality of primary air inlet apertures in the lower portionthereof, said apertures being inclined horizontally to the radius of theburner to give the air admitted there-'- from a circumferentialdirection and cause the same to circulate over said fuel sump adjacentsaid baille to form a premixture, said side wall also being providedwith a plurality of secondary air inlet apertures adjacent the topthereof for admitting additional air to form a combustion mixture, saidsecondary air inlet apertures being inclined horizontally to the radiusof the burner in the same direction as said primary air inlet apertures.5

4. Combustion apparatus of the character described comprising a burnerchamber having a bottom wall and an annular side wall, a fuel receivingsump of limited circumferential and radial extent formed von the bottomwall adjacent the side wall, a wall of the burner being provided with afuel inlet opening adapted to deliver fuel to said sump, a horizontallydisposed baille arranged in the center of the burner above said sump andpositioned to partially overlie the sump, said baiiie being mounted on acentral tube having a closed upper extremity provided with an airdischarge opening located below the top of the burner, said side wellbeing provided with a plurality of primary air inlet apertures in thelower portion thereof, said apertures being inclined horizontally to theradius of the burner to give the air admitted therefrom acircumferential direction and cause the same to circulate over said fuelsump adjacent said baiiles to form a premixture, said side wall alsobeing provided with a plurality of secondary air inlet aperturesadjacent the top thereof for admitting additional air to form acombustion mixture, said secondaryair inlet apertures being inclinedhorizontallyto the 80 radius of the burner in the same direction as saidprimary air inlet apertures.

BENVALJEAN.

CERTIFICATE OF CORRECTION.

Patent No. 2,068,441- r January 19, 193i BEN VALJEAN.

It is hereby certified that error appears in the printed specificationothe above numbered patent requiring correction as follows: Page 1, firstcolumn. line 6, for the word '"is" read may be; and line 9, for "may beread is; page 4 second column, line '69, claim 2, for "pump" read sump;one that the said Letters Patent shoulcibe read with these correctionstherein that the same may conform to the record of the case in thePatent Office.

Signed and sealed this 16th day of February, A. D. 1937.

Henry VanArsdale (Seal) Acting Commissioner of Patents.

